At 3:15 p.m., Topsham Fire Chief Brian Stockdale said the fire was still smoldering. The fire did not extend to an adjacent four-story building.

Crews received reports of an explosion and fire at the junkyard just before 1:30 p.m. and when they arrived they found flames rising from one of several old rail cars used to store reclaimed wire and other materials.

“I heard a boom and came out and saw the flames,” said security guard Ron Neron.

The yard abuts the Androscoggin River, and Stockdale said crews were “taking every precaution” to ensure runoff from the firefighting efforts didn’t end up in the river.

Tanker trucks brought water to the yard – where the pump “isn’t very good,” Stockdale said – to fill the car with water and then move it to where a catch basin can receive the water when the car is emptied.

The Maine state fire marshal was expected to investigate the cause of the fire because it was on the rails and Stockdale said he did not know how the fire started.

Firefighters from Topsham, Brunswick, Lisbon, Bowdoin, Bowdoinham and Freeport were at the scene.

Stockdale labeled the blaze a two-alarm fire because of the heat of the day and the need for so many tankers.